Original Vaccine Pock Institution, 275 



fied, unless with variolous matter. But to determine, a most 

 valuable fact, it is advisable to insert vaccine matter in one 

 arm and variolous in the other. No one would object to 

 this proposal, if the harmlessness of repeated insertion of 

 matter, fullv ascertained at this institution, were commonly 

 known. By this mode of procedure, a double test is applied, 

 and at the same time it will be shown that the state or dispo- 

 sition to be affected, or not, is alike to both kinds of matter. 

 " It is designed to relate our own experience ; and that has 

 not informed us that there is any such thing as spurious 

 matter in any proper sense of the term, i. e. a sort of matter 

 which produces an affection mistaken for the cow-pock, by 

 successive insertions of it from subject to subject. Matter 

 which produces an anomalous pock, either, on the succeed- 

 ing insertions, excites the regular cow- pock, or fails to ex- 

 cite a similar anomalous pock : this is, I say, according to 

 our experience. And in the cases of such anomalous pocks, 

 sometimes we have found the unsusceptibility of the small- 

 pox produced, and at other times not ; for in such cases we 

 always insisted upon reinocu'.ation. 



" II. Concerning the other supposed fact, which has with 

 many persons created an unfavourable opinion of vaccine 

 inoculation ; namely, the producing various disorders, even 

 of a new kind, we must have longer experience to arrive- at 

 a determination. The most experienced we are persuaded 

 will accede to this proposal : — If, on some occasions, seem- 

 ingly new forms of eruptive disorders appear, let it be re- 

 membered that they do so to accurate and extensive ob- 

 servers, not only in persons who have, but in those who 

 have not had the cow-pock. However, there docs appear 

 probable evidence that certain slight eruptive complaints are 

 the peculiar offspring of vaccination ; but that the formi- 

 dable diseases represented by some authors are the peculiar 

 effects of it, we must demur either to allow, or disallow, for 

 want of more experience. In the mean time we can safely 

 attest, that on the whole, much less frequently disorders su- 

 pervene to the cow-poek than to the small-pox inocula- 

 tion. Yet it is our duty to declare, that on </ood authority 

 in the course of the eight years practice of vaccination, four 



S 2 or 



